The human placenta is unique among organs because it is formed for a single purpose and is then discarded after use. When a fertilized egg attaches to the uterus, the placenta allows oxygen and nutrients to reach the developing fetus from its mother’s bloodstream and removes its wastes. In some cultures, the human placenta is thought of as an extension or companion to the baby and is reverentially disposed of. Eating the placenta, or placentophagy, is common among animals, but some people believe it has medical and psychological benefits. Some will consume it after birth or use it in alternative medicine or cosmetic products.
Cells called trophoblasts produce human chorionic gonadotropin (hCG) after fertilization to prepare the uterine lining for implantation. When this occurs, they burrow deep within and begin the process of placenta formation. A human placenta grows to about nine inches (22 cm) long and up to one inch (2.5 cm) thick, and it is covered with veining blood vessels. Its color is usually a dark red-blue to maroon, and it continues to grow throughout pregnancy.
A human placenta doesn’t just take care of the baby. It protects the mother from her own immune system, which sees the baby as an allograft, or foreign invader. The placenta secretes the hormone Neurokinin B and lymphatic immune suppressors to ensure the mother’s white blood cells will not attack it or the fetus.
While most human placentas do their job adequately, there are complications that can threaten the lives of mother and child. Placenta previa is a condition in which the placenta lies low in the uterus and covers the cervix. Serious bleeding may occur if it tears from dilation during the later stages of pregnancy. Placental abruption occurs during birth when the organ separates from the uterus before the child is born. Heavy and life-threatening blood loss can cause exsanguination in the mother and deprive the baby of oxygen.
In Western society, the human placenta is usually incinerated after birth. Various cultures, such as the Navajo, the Maori of New Zealand, and the Ibo tribe of Nigeria and Ghana, bury it with ceremony and reverence to protect the child and connect it with nature. Eastern cultures think of the placenta as a medicinal element. Highly processed placenta is often used in beauty creams as a protein enhancement.
Animals will often eat their birth membranes for not entirely understood reasons. Some people believe that eating the hormones and proteins in the human placenta relieves postpartum depression and assists in childbirth recovery. Called placentophagy, this practice is not very common in the West. Arrangements should be made with the hospital for proper preservation of the organ if the mother intends to consume it or have it encapsulated as a nutritional supplement. Various preparation guidelines can be found online.
